In medium to large size bridged IP networks hosts belonging to a substantial number of different subnets communicate with hosts belonging to their subnet. In most networks hosts belonging to the same subnet are typically connected to a small percentage of the total number of ports. This topology characteristic contributes to broadcast storms and/or network instability when IP broadcast frames are indiscriminately transmitted. Prior art networks have avoided this problem by configuring the network bridges in advance to direct IP broadcast frames to only those ports associated with the subnet address associated with the source host of the IP broadcast message.
While this solution works to eliminate the problem described above, it introduces another which is just as burdensome. In order to be effective the prior art solution requires intervention by a network administrator or the like each time a host is added to the network or when a host is moved from one port to another. In other words the solution requires advance configuration before the network is established and more significantly reconfiguration each time a change in the network takes place.